FXUS65 KPIH 052118
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
218 PM MST SAT DEC 5 2009

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT.

LOW PRESSURE SYSTEM IS OVER SOUTHEAST IDAHO THIS AFTERNOON. AN
AREA OF SNOW ACCOMPANIED THE LOW AND BROUGHT LIGHT AMOUNTS OF SNOW
TO THE SOUTHEAST CORNER OF IDAHO TODAY. THE LOW PRESSURE AREA WILL
REMAIN NEARLY STATIONARY THROUGHOUT THE OVERNIGHT HOURS AND
PRODUCE CONTINUED CHANCES FOR ISOLATED TO SCATTERED SNOW
SHOWERS...WITH THE SOUTHEAST CORNER OF THE STATE RECEIVING THE
BEST CHANCES. MODELS ARE SHOWING THAT THE HIGHER ELEVATIONS IN THE
IDAHO WASATCH COULD RECEIVE UP TO 4 INCHES TONIGHT. ON SUNDAY...A
SECOND LOW PRESSURE SYSTEM WILL DROP SOUTHWARD INTO SOUTHERN
OREGON. THIS LOW PRESSURE AREA WILL ABSORB THE SYSTEM THAT IS OVER
SOUTHEAST IDAHO AND WILL BECOME THE DOMINATE SYSTEM FOR THE
REMAINDER OF THE SHORT TERM. ISOLATED TO SCATTERED SNOW SHOWERS
WILL REMAIN POSSIBLE THROUGH MONDAY NIGHT AS THE LOW PRESSURE
SYSTEM MOVES THROUGH NEVADA AND UTAH. NOT LOOKING FOR SIGNIFICANT
ACCUMULATIONS...THE HIGHER AMOUNTS SHOULD STAY CLOSER TO THE TRACK
OF THE LOW IN UTAH. THE SOUTHEAST CORNER OF THE STATE STILL LOOKS
LIKE IT WILL HAVE THE BEST CHANCES AS WRAP AROUND FLOW MOVES
THROUGH THE REGION. THE HIGHER ELEVATIONS IN THE WASATCH COULD SEE
UP TO 7 INCHES THROUGHOUT THE ENTIRE EVENT...WHILE LOWER
ELEVATIONS COULD SEE UP TO 3 OR 4 INCHES. MUCH COLDER AIR IS
EXPECTED TO ARRIVE WITH THIS SECONDARY LOW PRESSURE SYSTEM. THE
COLDEST AIR WILL ARRIVE ON SUNDAY AND PERSIST THROUGH THE SHORT
TERM. HIGHS WILL BE IN THE TEENS DURING THIS TIME AND OVERNIGHT
LOWS WILL BE NEAR OR BELOW ZERO. EXPECT THE WINDS TO STAY UP
TONIGHT IN THE SNAKE PLAIN WITH THE LOW PRESSURE NEARBY. AS A
RESULT...WIND CHILL VALUES TONIGHT WILL FALL TO -5 TO -15 DEGREES
DURING THE OVERNIGHT PERIOD.

.LONG TERM...TUESDAY THROUGH SATURDAY. MODELS ARE IN GOOD AGREEMENT 
EARLY IN THE PERIOD. THEY ARE BOTH MOVING A TROUGH OUT OF AREA 
TUESDAY INTO WEDNESDAY. SO HAVE LEFT POPS ABOVE CLIMO IN THE 
SOUTHEAST HIGHLANDS AND REDUCED POPS ELSEWHERE.  COLD CANADIAN 
NORTHERLY FLOW WILL FOLLOW THIS TROUGH WITH WELL BELOW AVERAGE 
TEMPERATURES ON TUESDAY AND WEDNESDAY.  HAVE SLIGHTLY REDUCED 
TEMPERATURES ON TUESDAY AND WEDNESDAY. THE NEXT SYSTEM COMES AT THE 
END OF THE PERIOD.  BOTH MODELS ARE BRINGING IN A SYSTEM FRIDAY INTO 
SATURDAY FROM THE PACIFIC THROUGH CALIFORNIA THOUGH THEY ARE OFF IN 
TIMING AND INTENSITY.  HAVE KEPT POPS ABOVE CLIMO FOR FRIDAY AND 
SATURDAY. ADDITIONALLY...HAVE SLIGHTLY INCREASED TEMPERATURES AT THE 
END OF THE WEEK. WYATT

&&

.AVIATION...AN UPPER LEVEL LOW IS CURRENTLY OVER SOUTHEAST IDAHO 
MOVING SLOWLY SOUTH. EXPECT VICINITY SNOW SHOWERS THROUGH SUNDAY 
WITH LOW TO MID LEVEL CIGS THROUGH SUNDAY.  CIGS SHOULD REMAIN VFR 
EXCEPT IN BRIEF PERIODS OF SNOW SHOWERS OVER TAF SITES. SNOW SHOWERS 
WILL BE MOSTLY IN THE MOUNTAINS OVER THE SOUTHEAST HIGHLANDS.
WYATT

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$